There's yet another heatwave hitting the UK and US right now, and unlike my colleagues, I'm a fair-weather runner, so it's officially too hot for me to run outdoors.
But my once-a-week cardio sessions are non-negotiable, so I've turned to the gym and the best treadmills instead. I'm not really a commercial gym user, but if you do have access to a treadmill at home or a local gym, I recommend hopping on and giving this 20-minute running HIIT workout a try.
You'll move between paces, including walking, jogging, and running, and deal with inclines, flat roads, and some speedwork. It's helping me stay on top of cardio without sweltering in the sunshine, and I'm very grateful for it.
Don't worry, if you're not much of a runner, this whole routine is beginner-friendly. You get to set the pace of your walks, jogs, and runs, and I'll only ever give you guidelines or recommendations.
What is the workout?
You'll move between paces, including walking, jogging and running, and deal with inclines, flat roads and some speedwork.
- Warm-up block, 5 mins: Spend 60 seconds at walking pace; this should be something you could comfortably maintain for 30 minutes uninterrupted. Next, spend 2 minutes at jogging pace; you should be able to hold a conversation. Increase incline to 6% and maintain jogging pace for 60 seconds, then drop the incline to flat road and hit your run pace for 60 seconds.
- Incline block, 7 mins 30 sec: Walk for 30 seconds, jog 30 seconds, sprint 30 seconds. Next, jog 90 seconds at 6% incline. Drop to a walk for 90 seconds at 9% incline. Jog 60 seconds at 6% incline, then maintain jogging for 30 seconds at 9% incline. Finally, walk for 60 seconds on a flat road.
- Speed play, 7 mins 30: Jog for 60 seconds, sprint for 30 seconds, then jog for 30 seconds, all on a flat road. Sprint again for 30 seconds, then jog for 30 seconds and drop down to a 30-second walk. Repeat from the top.
Let's take a look at a popular way of measuring effort, which will help you determine your pace without a coach: rate of perceived exertion, or RPE. This will help you work out where you sit for a walk, jog and run out of 10 (10 being your absolute maximum output).
For a walk, as briefly mentioned, it should be something you could maintain happily enough for 30 minutes or so — think a 3-4/10. Your jogging pace is around a 5-6/10; you can still have a conversation with someone next to you, but you're exerting a little more effort.
Your run pace is more like a sprint, think between 7-9/10. This should be a hard effort that you can only maintain for a short time.
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The inclines are 6 and 9%, but these are only guidelines, so you can adapt these to your ability. If you're unable to hit the specified times at your given pace, it could be worth making some adjustments.
As you push through the inclines, slightly lean your weight forward without rounding your back, as this will help you engage your glutes. Generally, uphill climbs engage more of your back body, like the lower back and hamstrings, so just be sure to brace your core as you walk, jog, or run to protect your spine.
During the faster running efforts, use your arms to help with forward propulsion, and keep your strides even as you strike the treadmill. Try to avoid crossing your arms over the front of your body, as this reduces efficiency, and also avoid running too far back or forward on the running belt.
Pace yourself properly because fatigue will set in, so you need to think about keeping something back during the warm-up. This is about building speed, power and endurance, so try to keep some energy in the tank for those final rounds.
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Sam Hopes is a level 3 qualified trainer, a level 2 Reiki practitioner and fitness editor at Tom's Guide. She is also currently undertaking her Yoga For Athletes training course.
Sam has written for various fitness brands and websites over the years and has experience across brands at Future, such as Live Science, Fit&Well, Coach, and T3.
Having coached at fitness studios like F45 and Virgin Active and taken on both 1:1 and group, Sam now primarily teaches outdoor bootcamps, bodyweight, and kettlebells.
She also coaches mobility and flexibility classes several times a week.
Sam has completed two mixed doubles Hyrox competitions in London and the Netherlands and finished her first doubles attempt in 1:11.
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